Circuit breaker and closer for alternating currents.



No. 792.020. PATENTED JUNE 13, 1905. A. GRAY.

CIRCUIT BREAKER AND CLOSER FOR ALTERNATING OURRENTS.

APPLICATION FILED SEPT. 7, 1904.

3 SHEETS-SHEET 1.

BY AND WGRA flmw a;

H \S TTORNEYS PATENTED JUNE 13, 1905.

A. GRAY.

CIRCUIT BREAKER AND CLOSER FOR ALTERNATING CURRBNTS.

APPLICATION FILED SEPT. 'I 1904.

3 SHEETS-SHEET 2.

ANDREW GRAY, W H\S ATTORNEYS.

PATENTED JUNE 13, 1905.

A. GRAY. CIRCUIT BREAKER AND CLOSER FOR ALTERNATING GURRENTS.

APPLICATION FILED SEPT. 7. 1904.

3 SHEETS-SHEET 3 UNITED STATES Patented June 13, 1905.

PATENT OEEIcE.

ANDREIV GRAY, OF LONDON, ENG-LAND, ASSIGNOR, BY MESNE ASSIGN- MENTS, TOMAROONI WIRELESS TELEGRAPH COMPANY OF AMERICA, A CORPORATION OF NFNVJERSEY.

CIRCUIT BREAKER AND CLOSER FOR ALTERNATING CURRENTS- SPECIFICATIONforming part of Letters Patent No. 792,020, dated June 13, 1905.

Application filed September '7, 1904. Serial No. 223,614.

To all whom it may concern.-

Be it known that I, ANDREW GRAY, electrician, a subject of the King ofGreat Britain, residing at 18 Finch Lane, in the city of London,England, have invented certain new and useful Improvements in CircuitBreakers and Closers for Alternating Currents, of which the following isa specification.

This invention relates to circuit-closers for heavy alternatingcurrents; and its object is to prevent sparking, which is done accordingto this invention by causing the current from the dynamo, whenever it ispassing, to hold the contact-maker stationary, so that it can only bemoved when the current is at Zero between two alternations. For thispurpose the contact-maker is carried by the armature of an electromagnetenergized by a coil in the dynamo-circuit.

Figure 1 is a diagram illustrating the invention in its simplest form.Figs. 2, 3, 4, and 5 are similar views showing modifications. Fig. 6 isa diagram showing the application of the invention to the automatictransmission of messages by wireless telegraphy. Fig. 7 is a diagramshowing a dot-and-dash signal.

a is an alternatingcurrent dynamo, one branch of whose circuit includesan electromagnet]; and a contact 0, while the other branch passesthrough the armature cl of the electromagnet to a contact 0. Thecontacts 0 and e are held apart by a spring f.

z is a key held up by a spring A. If the key g be pressed down, thecontacts 0 and (a are brought together, and the circuit is closedthrough the magnet Z), causing it to attract its armature (Z, so thatthe circuit remains closed when the key 9 is raised until the currentreaches a zero point, whereupon the 4 springfseparates the contacts 0and a without sparking, because at this time there is no current. Fig. 2shows a similar arrangement; but in this case the key 9, instead ofbringing the contacts a and 6 together mechanically, does soelectrically. For this purpose it is connected as a shunt to one branchof the dynamo-circuit and carries a contact 7', which is opposite to acontact 1* in the other branch, so

that when the key is depressed the dynamocircuit is closed through themagnet 71, thereby bringing the contacts 0 and 0 together.

Fig. 3 shows an arrangement exactly similar to Fig. 2, except that thekey is operated electrically instead of mechanically. For this purposeit forms the armature of an electromagnet l in a local-battery circuitwhich is closed by a key m.

In the transmittinginstruments for wireless telegraphy and in othercases it is often desir able to keep the load on the dynamo constant.For this purpose the back contact is connected to the dynamocircuitthrough another circuit electrically equivalent to thetransmitting-circuit. In such a case the above-described arrangement isduplicated, as shown in Fig. I, each half of this arrangement beingexactly the same as Fig. 3, and has the same letters. a is a coilforming part of the wireless-telegraph transmitter, and 0 is aresistance equal to the resistance of the transmitter. Fig. 5 shows anexactly-similar arrangement, which is rendered more compact by combiningthe magnets 7) and Z into a doublewound magnet and by employing a singlearmature ril, carrying two contacts (5.

The arrangements described above render it possible to employ anordinary Vheatstone automatic transmitter in wireless telegraphy, whichhas hitherto been impracticable when any considerable power has beenused.

Referring to Figs. t and 5, l have shown the signaling-key m in anintermediate position. Normally, however, the back contact of such keyshould lie against the contact which is in circuit with the upper magnetZ.

Fig. 6 shows the application of the arrangement shown in Fig. 5 to theautomatic transmission of wireless signals by means of a perforatedtape, as in an ordinary telegraph instrument. The pin-wheel y), by whichthe perforated tape 9 is driven, is directly geared to the dynamo a, asshown, or is otherwise driven synchronously with it, so that the speedof the perforated paper and the times at which the contacts are made canbe adjusted to coincidence with the time of sparking.

a is a crank-wheel geared to the wheel p and connected by the rod .9 tothe rocking lever t, which causes the needles u to reoiprocate'up anddown. If these needles in their upward movement come against the paperg, they are arrested before the stops 0) (which are connected to them bythe lever move the key on suflicient to close the local-battery circuit;but if one of the needles passes through ahole in the paper the key mcloses one or other of the circuits. In this way it is possible toutilize the alternator with maximum economythat is to say, instead ofrequiring afrequency so high that the duration of contact required for adot will insure at least one spark occurring within the intervalcomprised in a dot the transmitting is so timed that the contact of adot is made when the spark is about to occur.

With a low frequency a normal speed of transmisslon can be obtained bymaking one spark for a dot and three sparks for a dash and missing onespark for a space between the elements of a letter, three sparks for thespace between the letters, and five sparks for the space between thewords in a sentence, as shown at Fig. 7. v

At higher frequencies moderate speed of transmission can be obtained bymaking the spaces longerthat is to say, missing a greater number ofsparksthough of course at a sac.

rifice in efliciency; but, again, should a higher speed of transmissionbe required the first-described spacing can be adopted for the higherfrequency.

What I claim is 1. In a circuit breaker or closer for alternatingcurrents, two circuits, means, comprising a magnet for opening onecircuit while the current is at or near zero, said means operating tosimultaneously close the other circuit, substantially as described.

2. In a circuit breaker or closer for alternating currents, twocircuits, a movable member carrying contacts for closing said circuits,means for opening one of said circuits while the current is at or nearzero, said means operating to simultaneously close the other circuit,substantially as described.

3. In a circuit breaker or closer for alternating currents, twocircuits, automatic means for opening one circuit while the current isat or near zero, and to simultaneously close the other circuit,substantially as described.

4. The combination of an alternating-current generator, a circuitconnected to it, a contact and an electromagnet in one branch of thecircuit, an armature to the electromagnet, a contact carried by thearmature in the other branch of the circuit, a spring connected to thearmature and tending to separate the contacts, a second circuit throughthe electromagnet and means for closing this circuit. V

5. The combination of an alternating-current generator, a circuitconnected to it, a contact and an electromagnet in one branch of thecircuit, an armature to the electromagnet, a contact carried by thearmature in the other branch of the circuit, a spring connected to thearmature and tending to separate the contacts, a second circuit throughthe electromagnet, a circuit-closer in this circuit, an electromagnetoperating it, a local battery energizing the latter electromagnet andmeans for closing the battery-circuit.

6. The combination of analternating-current generator, two circuitsconnected to it, a contact and an electromagnet in one branch of eachcircuit, an armature to each electromag net, contacts carried by thearmatures in the other branches of the circuits, means constantlytending to separate the contacts, a second circuit through eachelectromagnet, and means for simultaneously closing one of the lattercircuits and breaking the other.

7. The combination of an alternating-current generator,'two circuitsconnected to it, a contact and an electromagnet in one branch of eachcircuit, an armature to each electromagnet, contacts carried by thearmatures in the other branches of the circuits, means constantlytending to separate the contacts, a second circuit through eachelectromagnet, circuit-closers in these circuits, electromagnetsoperating them, a local battery energizing these electromagnets, andmeans for simultaneously closing the battery-circuit through one magnetand breaking it through the other.

8. In a circuit breaker or closer for alternating currents, thecombination of apivoted contact-maker, a contact carried by it and connected to one branch of the circuit, a second contact opposite to thefirst and connected to the other branch of the circuit, a spring actingon the contact-maker and tending to separate the contacts, an armaturecarried by the contact-maker, an electromagnet energized by the currentacting on the armature and tending to bring the contacts together, andan ordinary automatic telegraph-transmitter closing a circuit throughthe electromagnet.

9. The combination of an alternating-current generator, a circuitconnected to it, a contact and an electromagnet in one branch of thecircuit, an armature to the electromagnet, a contact carried by thearmature in the other branch of the circuit, a spring connected to thearmature and tending to separate the contacts, a second circuit throughthe electromagnet, and an ordinary automatic telegraphtransmitterrevolving synchronously with the generator closing this circuit.

10. The combination of an alternating-current generator, a circuitconnected to it, a contact and an electromagnet in one branch of thecircuit, an armature to the electromagnet, a contact carried by thearmature in the other branch of the circuit, a spring connected to thearmature and tending to separate the contacts,- a second circuit throughthe electro- IIO magnet, a circuit-closcr in this circuit, aneleetromagnet operating it, a local battery energizing the latterelectromagnet, and an ordinary automatic telegraph-transmitter revolvingsynchronously with the generator closing the battery-circuit.

11. The combination of an alternating-current generator, two circuitsconnected to it, a contact and an electromagnet in one branch of eachcircuit, an armature to each electromagnct, contacts carried by thearmatures in the 'other branches of the circuits, means constantlytending to separate the contacts, a second circuit through eachelectromagnet, and an ordinary automatic telegraph-transmitter revolvingsynchronously with the generator simultaneously closing one of thelatter circuits and breaking the other.

12. The combination of an alternating-cur- ANDREW GRAY.

l/Vi tn esses G. H. GREEN, VVILMER M. HARRIs.

